General

sounds like she's not the woman for you broh

My ex thought I was actually gross for liking fat women...notice the ex part? XD

you have to respect what she wants. having said that, I have met a lot of guys, both here and irl, who claim to be into fat women but end up with a skinny one. how come? are you afraid of social stigma? or do you think it's just a coincidence?

These two posts are quoted to help you reread them. I did this because the first quote is important because if she's not into gaining they're right, make your current partner your ex because of a lack of compatibility. As far as the second post goes I believe the reference is obvious.

What wife? You have no wife anywhere near your profile

The thing is : looks are only one part of attraction in a relationship.
Yes I love very fat SSBBW's, my wife knows this, but she doesn't want to get that big herself for health reasons, and I respect that.
Body size is only one thing, I still find her attractive at 17-18 stone, and I still love her as a person in every other way, we have a great marriage.
If a marriage is only based on looks, then it isn't much of a marriage in my opinion (not aiming that directly at your marriage, just a point in general).
You have a few simple choices, accept she wants to slim down a bit, and stay with her because you love her in many other ways.
Split up simply because you don't find her attractive.
Stay together but find your sexual gratification with her permission, in other ways, either through porn/masturbation or an open relationship.
Fats